The invention relates to an assembly for a vehicle body.
Many assemblies in motor vehicles, including in particular A-pillars, are manufactured from sheet steel in monocoque construction. Shell structures from aluminum are also known in the course of lightweight construction. Among these are assemblies designed as aluminum casting assemblies with welded extruded aluminum profiles. While steel construction dictates a relatively high weight of the assemblies, aluminum construction, both in monocoque and casted construction, meets higher demands in terms of lightweight construction. Only assemblies made from fibrous composites, including hereunder those made from carbon fiber plastics (CFRP), provide a still greater potential for designs with lightweight construction. Due to galvanic corrosion and differential thermal expansion, however, the possibility for combination with lightweight metals is limited. Profile assemblies made from fiber composite plastics which are manufactured through a braiding or winding method also have only limited design possibilities. Moreover, the attachment of functional components, such as door hinges, sealing profiles and the like, is difficult. In addition, the connection of the profiles with one another in a load-bearing node, such as an A-pillar, is complex. In contrast, extrusion materials have a strong degree of freedom in design, however they have a rather brittle fracture behavior in the case of overloading, which is disadvantageous in particular in the case of crash-sensitive assemblies such as an A-pillar. Surface assemblies, such as those produced through a wet pressing method or RTM method, among these in particular CFRP, have a high strength, however they are limited in design.
Based on this prior art, the object of the present invention is to provide an assembly for a vehicle body, having the following assembly components: a sill, roof frame, hinge pillar, outer shell and inner shell, said assembly meeting, on the one hand high, requirements of rigidity and firmness, and, on the other hand, offering a high degree of structural possibilities and options for the integration of connecting means, but which nevertheless has a low weight.
According to the invention, this and other objects are achieved by an assembly for a vehicle body, wherein the sill and the roof frame are formed by hollow profiles. The hinge pillar is made from an extruded fibrous composite. The sill, the roof frame and the hinge pillar are surrounded on the outer side and the inner side, at least partially, by the outer shell and the inner shell, such that the aforementioned assembly components form a composite unit.
By way of this overall construction according to the invention from hollow profiles, extruded components and shells, an assembly for a vehicle body is achieved which can meet complex requirements such as those of high rigidity and firmness, a high degree of freedom in design and the possibility of the integration of secondary functions, such as the attachment of door hinges, seals, equipment components and the like, at the lowest possible weight. In particular, the use of an extruded component for the design of the hinge pillar is especially advantageous, as during the manufacturing thereof, any connecting elements which could contribute to a stable composite unit of the assembly components can already be pressed in.
According to an advantageous development, the hollow profile is formed from a wound, braided or extruded fibrous composite, preferably a carbon fiber composite material. These hollow profiles are characterized by a very good rigidity and firmness and can be manufactured economically.
The assembly according to the invention is further advantageously characterized in that the outer shell and inner shell are formed from a fibrous composite, preferably a carbon fiber composite material, which has a fiber structure or fiber fabric, or which is formed at least partially from a metallic material. Outer and inner shells manufactured in this way form an effective composite unit and contribute to a transfer of force between the hollow profiles and the hinge pillar such that, for example in the event of a crash, the assembly is substantially maintained even with partial deformation or destruction of one of the assembly components.
An advantageous development provides that the fibers in the fibrous composite of the outer shell and the inner shell are oriented, continuous fibers, wherein the fibers are aligned in the main loading direction of the assembly. In this way, the rigidity and firmness of the assembly is increased, and a deformation under the action of mechanical load is effectively counteracted.
To obtain a high degree of design freedom with very good rigidity and firmness, it is advantageously provided that the extruded fibrous composite of the hinge pillar is preferably formed from a carbon fiber composite material, and further advantageously, comprises fibers having a fiber length from 8 to 40 mm, preferably from 10 to 30 mm.
The assembly components are further advantageously connected to one another by a high-strength adhesive bond. The bond between the assembly components is thereby promoted, which contributes to the stability of the assembly according to the invention.
According to an advantageous development, the composite unit of the assembly components has a ductility which is sufficient to absorb energy in the event of a crash, and to ensure the connection of the assembly components even with partial destruction of the individual assembly components.
In order to provide a good connection between the hinge pillar and both the outer shell and the inner shell, it is further advantageous to form the hinge pillar in a meandering shape.
A further advantageous development provides that the hinge pillar includes further components, such as fixtures for door hinges and door checks, wire harness feedthroughs, equipment components, for example speakers, fasteners for interior trim components, connecting elements and the like. This increases the design freedom and thus the functionality of the assembly according to the invention.
The assembly for a vehicle body according to the invention is, in particular, an A-pillar. Because in a vehicle particularly high demands are made of an A-pillar, both in terms of mechanical properties such as ductility, rigidity and firmness, as well as in terms of design options, the assembly according to the invention is particularly well-suited for the formation of an A-pillar.
In particular the following advantages result due to the embodiments according to the invention:                Mechanical properties such as torsion strength and static and dynamic rigidity can be improved;        The firmness of the assembly is increased;        Intrusions during side impact and when force is applied to the roof frame are reduced by the shape- and material-optimized construction;        The assembly comprises a very good composite unit of the assembly components, which even under partial impairment of one of the assembly components still provides sufficient stability;        The weight of the assembly according to the invention is lower with equal properties than the conventional construction of steel or aluminum; and        An integration of other components such as equipment components, fastening devices or connecting elements is possible.        
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.